Abstract:
A motor control system accurately and reliably controls the speed of a motor (14) so that the motor (14) operates in accordance with a predetermined motor speed profile, and therefore does not exceed a predetermined safe speed, decelerates at a controlled rate, maintains a safe minimum speed, and does not turn in reverse. If the motor (14) operates out of these limits, a malfunction is indicated and the control system halts operation of the motor (487). The motor speed is determined using an electronic tachometer (18) that analyzes the current (66, 68, 70) in at least two phases of the motor (60, 62, 64) to provide extremely precise and reliable velocity information for the motor (14).
Abstract:
A microcomputer controlled power tool (10) including a semiconductor control device (64) connected to the motor (66), one or more sensors (36, 58), and a microcomputer (50) interfaced to a keyboard (28) and digital display (30) for monitoring and controlling various operating conditions and parameters of the power tool.
Abstract:
A drive motor assembly for a power driven wheelchair comprises: a stator housing for containing field coils of a stator of the motor assembly; at least one sensor disposed in the stator housing for sensing rotation of the motor; a memory storing motor error parameter data including data of errors of the at least one sensor, the memory being embedded in the stator housing; and a connection for accessing the error parameter data of the memory from the stator housing. The motor error parameter data may be accessed from the embedded memory of the drive motor by a programmed motor controller for use in controlling the drive motor. Also, the motor error parameter data may be embedded in the drive motor by the steps of : controlling the motor through at least one predetermined drive pattern; sensing motor rotation during the drive pattern and generating signals representative thereof, deriving error parameter data of the drive motor from the generated signals; programming a memory with the derived error parameter data; and embedding the memory in the drive motor.
Abstract:
A brush type DC motor (10) having an armature (15) and positive and negative power leads is provided. The motor includes an RFI choke (12) as a transformer in series with at least one of the positive and negative power leads to amplify current such that rotation of the armature (15) can be detected based on monitoring a voltage relating to the amplified current. Conditioning circuitry (14) is constructed and arranged to condition the voltage for detecting rotation of the armature.
Abstract:
The invention relates to a motor which can be electronically switched, whereby the output stage can be controlled via an electronic control unit by means of PWM control signals and fed by power supply voltage. According to the invention, a limit for a maximum load with overload protection is achieved in that the pulse width of the PWM control signals for the output stages can be reduced to widths which prevent an overload of the motor and the electronic components by limiting motor power depending on the value of power supply and the predetermined desired value of the PWM control signals, at least, once the nominal voltage of the motor is exceeded.
Abstract:
A device with an electromotor (10) has a microcontroller (12) for influencing at least one motor function and a non-volatile storage element (14) for storing at least one variable as a specification for this motor function. The device also has an interface (13a) for a data line (13) for transmitting the at least one variable, especially a current limit value (Iref), from or to a storage element (14) with the help of the microcontroller (12) and optionally, via an internal data bus (15). The invention also relates to the use of the device in ventilator batteries and to programme-controlled current limitation for running up an electromotor (10).
Abstract:
In a preferred embodiment, a high-frequency, pulse-width-modulated, power-transistor, DC motor speed controller having current limiting in both drive and regenerative modes, essentially constant ramping rates regardless of whether or not the operator switches to neutral before changing direction, a simple sequencer which controls the timing of four functions - both drive and regenerative current measuring circuits and both drive and regenerative transistors, a highly effective transistor filter capacitor arrangement, and circuitry in which the level of regenerative current is used as an input to control the current under which the direction relays switch.
Abstract:
An apparatus and method of protecting a centrifuge from rotor overspeed and resultant mishap by computation of the rotor moment of inertia is disclosed. In the preferred embodiment, a centrifuge is driven by a rotor (10) mounted on a shaft (14) which shaft is in turn driven by a constant current motor (16). A tachometer (20) for detecting angular velocity of the drive shaft is used. A desired and ultimate centrifuge operating speed is selected by the operator. The times at which the rotor passes through discrete speeds are recorded and from the time difference the moment of inertia is computed. The moment of inertia can thereafter be utilized to discretely identify or ''finger print'' rotors to disqualify certain rotors from use in particular centrifuge protocols and establish gross limits of centrifuge operating speed.
Abstract:
A cordless power tool may include tool identification circuitry to provide a tool identification signal to a battery pack. The tool identification signal may be representative of data particular to the cordless power tool. A method may include coupling a battery pack to a cordless power tool, and providing a tool identification signal to the battery pack from the cordless power tool once the battery pack is coupled to the cordless power tool, the tool identification signal representative of data particular to the cordless power tool.